EDI: the details
Each document has a standardized message. In ANSI X12, the dominant standard in North America, 850 is the purchase order, 856 the advance ship notice and 810 the invoice; in Europe the most used standard is EDIFACT, where the same documents are called ORDERS, DESADV and INVOIC. Messages travel over value-added networks or direct connections such as AS2, and each industry adds its own implementation guides.
It’s a common requirement for selling to big retail and to automotive: without it, you don’t get in as a supplier. For a mid-sized company, the cost isn’t in the format but in connecting it to the ERP and handling exceptions: the order with an unknown item number, the price that doesn’t match, the ship notice that needs correcting.